Google Earth API Moving a polygon

Question

Hi,

I just starting coding with Google Earth using the GEPlugin control for .Net and still got a lot to learn.

What has got me puzzled is when I try to drag a polygon.

The method below is called whenever the mousemove event fires and should be moving each point of the polygon while retaining the orginal shape of the polygon. The lat / long for each point is changed but the polygon does not move position on the map.

Will moving a point in a polygon cause it to redraw, do I need to call a method to force a redraw or perhaps do something else entirely?

Thanks!

private void DoMouseMove(IKmlMouseEvent mouseEvent)
    {
        if (isDragging)
        {
            mouseEvent.preventDefault();

            var placemark = mouseEvent.getTarget() as IKmlPlacemark;

            if (placemark == null)
            {
                return;
            }

            IKmlPolygon polygon = placemark.getGeometry() as IKmlPolygon;


            if (polygon != null)
            {
                float latOffset = startLatLong.Latitude - mouseEvent.getLatitude();
                float longOffset = startLatLong.Longitude - mouseEvent.getLongitude();

                KmlLinearRingCoClass outer = polygon.getOuterBoundary();
                KmlCoordArrayCoClass coordsArray = outer.getCoordinates();

                for(int i = 0; i < coordsArray.getLength(); i++)
                {
                    KmlCoordCoClass currentPoint = coordsArray.get(i);
                    currentPoint.setLatLngAlt(currentPoint.getLatitude() + latOffset, 
                        currentPoint.getLongitude() + longOffset, 0);
                }
            }
        }
    }